
Last year we had a single flowering weed, which bloomed late in the summer. The weed was huge, maybe 7' tall. It was allowed to remain established because it appeared overnight and was covered with bees--they loved it! The plant put out seeds in pods--must be a legume, also good for the soil. There might have been 2000 tiny seeds in each pod.
I knew as soon as I saw the bees went for it that we needed this plant. In the spring it came up everywhere--it was easy to tell that this was my plant. I thinned some out, but left a large bank of what I now know to be "Rocky Mountain Bee Weed".
Wikipedia informs reader Cleome serrulata is used in the southwestern U.S. as a food, medicine, or dye. It is called waa’ in the Navajo language. The National Wildlife Refuge Rocky Mountain Arsenal web page tells that bees and insects are attracted to the rich nectar from the blossoms of this native plant, and that the seeds are often consumed by morning doves. Among other uses, the site recommends boiling the leaves as greens, eating the seeds or making them into flour. I just want all bee-keepers to let some of these grow in their alleys. If there's any rain at all, you probably won't need to water.